Aspects of the present disclosure relate generally to wireless communications and, more particularly, to method and apparatus for uplink resource allocation and transport block size determination over unlicensed spectrum.
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of an emerging telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by improving spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
A significant amount of unlicensed spectrum is unused or lightly used. Such unlicensed spectrum may be useful for various types of wireless communications, including, for example, rural broadband deployments in difficult to reach places, providing broadband access in underserved markets, and Machine-to-Machine (M2M) communications. As such, unlicensed spectrum use may provide additional bands and significantly enhance the evolution of wireless communications over a wide variety of wireless access technologies in terms of both capability and functionality. The use of LTE over unlicensed spectrum may be referred to as “LTE-U.” Using LTE over unlicensed spectrum may necessitate using techniques for various aspects of wireless communications that are different from those used for traditional LTE. As such, standardized techniques related to uplink (UL) resource allocation and transport block size (TBS) in LTE over licensed spectrum may not be successfully applied to use of LTE over unlicensed spectrum (e.g., in LTE-U).
As such, improvements in uplink resource allocation and transport block size (TBS) determination over unlicensed spectrum may be desired.